Strapping device having position determination of the package and method for arranging an edge protection element

ABSTRACT

The invention describes, and illustrates, a strapping apparatus for strapping packages using a strapping means, having a packaging table, on which the package is guided through the apparatus, having vertical supports, which are arranged laterally in relation to the packaging table and on which a press plate can be displaced vertically, having an arrangement device for arranging an edge-protection means, it being possible for the arrangement device to be displaced horizontally on the press plate along a movement path, and having a controller, which moves the arrangement device into an arrangement position for arranging the edge-protection means on the package, wherein a means for sensing the position of the package is arranged in an entry region of the strapping apparatus, and the position-sensing means senses an entry position of the package during the entry movement thereof.

The invention relates, in the first instance, to a strapping apparatus for strapping packages using a strapping means, having a packaging table, on which the package is guided through the apparatus, having vertical supports, which are arranged laterally in relation to the packaging table and on which a press plate can be displaced vertically, having an arrangement device for arranging an edge-protection means, it being possible for the arrangement device to be displaced horizontally on the press plate along a movement path, having a controller, which moves the arrangement device into an arrangement position for arranging the edge-protection means on the package.

Strapping apparatuses are well-known installations of different sizes which use bands to strap packages in order to ensure reliable transportation or reliable storage. Installations of appropriate size are known for relatively large packages, which are usually stored on carriers, e.g. pallets. The packaging table of said installations is formed from a roller conveyor, on which the package is moved through the apparatus. Vertical supports, which retain a press plate which spans the packaging table, are arranged laterally in relation to the package. The press plate can be displaced in the upward and downward direction along the vertical supports. Running along the press plate, the vertical supports and in the packaging table is a band channel, around through which is guided the strapping means—starting from an insertion and closure device. Once the band has been inserted into the band channel, a retraction operation takes place, during which the band is tensioned around the package.

-   -   1. The packages often have sensitive edges which, during         retraction and tensioning of the band, around the package, are         subject to a not inconsiderable risk of damage. In order to         avoid damage, an edge-protection means is applied prior to the         strapping operation, said edge-protection means coming to bear         between the package and the band and effectively preventing         damage to the edge of the package, for example as a result of         the band cutting in. An arrangement device is provided in order         to arrange the edge-protection means on the package. This draw         the edge-protection means usually from a supply magazine and are         moved, by a controller, into an arrangement position in the         vicinity of the package. In order to protect the upper edges of         the package, the applicant has provided arrangement devices for         edge-protection means which can be displaced along a running         rail on the press plate. To this extent, reference is made to         the prior-art document DE 10 2013 004 449 A1. On this subject,         reference is also made to the applicant's own prior-art document         DE 10 2013 004 448 B3, which discloses an apparatus as described         above and, in particular, an edge-protection magazine which is         to be utilized therein.

In order for the arrangement device, which can be displaced on the press plate, to be positioned correctly, prior art for which we have no documentary evidence discloses the use of a corresponding sensor. In a specific case, this is implemented by a photocell fastened on the arrangement device. This photocell makes it possible for the controller to detect the edge of the package as the arrangement device travels over the same. Once the edge of the package has been detected, the arrangement device is stopped, is displaced back by a defined distance, and has then reached the arrangement position. In order to ensure that the edge of the package is detected, it is necessary for the package to be arranged beneath the press plate and be located in the its strapping position.

The operation of detecting the edge of the package takes place in a sure and reliable manner in this prior art, and therefore misplacements of the edge-protection means are reliably avoided. However, there is a constant need to increase the throughput speeds of packages in strapping machines. It is, indeed, the case here that the operation of detecting the edge of the package proves to be an advantageous feature, since misplacements of edge-protection means, which adversely affect the throughput, can be reliably avoided. This is relevant, in particular, when the packages which are to be strapped comprise a plurality of individual parts, and these are possibly not stacked quite neatly one upon the other, deviations from the ideal cubature arising as a result.

The prior art also uses a strapping method in which the package enters into the apparatus and remains in a strapping position beneath the press plate. The arrangement device then travels from an actual position in the direction of the package until its sensor—in the specific exemplary embodiment a photocell—detects the edge of the package. The arrangement device is then displaced back by a fixed, predefined value, so that it is then located in its arrangement position. Following this, the press plate is displaced downward, the edge-protection means being retained between the press plate and package. The arrangement device travels back into its starting position. The strapping operation takes place. Thereafter, the press plate is raised and the package is moved out of the apparatus.

The invention also includes a method of the generic type described above.

With there being a general need of continuously optimizing the throughput through strapping apparatuses, it is precisely this which is the object of the invention, this being achieved by an apparatus according to the features of claim 1, and the following dependent claims, and by a method according to alternative independent claim 5, and the associated dependent claims.

The apparatus according to claim 1 is characterized in that a means for sensing the position of the package is arranged in an entry region of the strapping apparatus, and the position-sensing means senses an entry position of the package during the entry movement thereof.

The essential advantage of the invention is that the means for sensing the position of the package is now arranged such that the position-sensing operation can be determined while the package is still entering, before the strapping position is reached.

For this purpose, a specific embodiment provides for the position-sensing means to be arranged laterally in relation to the packaging table. The lateral arrangement of the position-sensing means has the essential advantage that, in contrast to the prior art, the position-detecting operation takes place via the side surface of the package, which can give more precise results. It is also significant that a row of apparatus components are arranged laterally in relation to the packaging table, it being possible for the position-sensing means to be fastened straightforwardly, without any great amount of additional outlay, on said components. Finally, this means that there is no need for any additional retaining components which adversely affect the operating region of the apparatus.

It is particularly preferred if the position-sensing means is arranged on one of the vertical supports.

Provision is also made for the arrangement device to have a distance counter, which senses a route covered by the arrangement device along its movement path. The distance counter which is present on the arrangement device makes it possible, in conjunction with a method which will be described in more detail hereinbelow, to utilize the position sensing in the entry region in order to displace the arrangement device over a defined distance into the anticipated strapping position of the package, without the arrangement device itself requiring a sensor for sensing the edge of the package and for determining the arrangement position.

Utilizing, in particular, the apparatus described above, the object of the invention is also achieved by a method having the features of claim 5, in particular having the characterizing features of claim 5, according to which the position-sensing means senses the position of the package on the packaging table while the package is entering,

-   -   the controller uses the entry position to calculate a strapping         position of the package,     -   the controller takes account of the calculated strapping         position to determine the arrangement position of the         arrangement device,     -   the controller determines the distance which is to be covered by         the arrangement device from an actual position to the         arrangement position,     -   the controller causes the arrangement device to move into the         arrangement position.

As can be gathered from the method steps, the position-sensing means arranged in the entry region of the package makes it possible to determine the strapping position of the package beneath the press plate before the package has actually reached this strapping position. The apparatus controller is therefore then capable of displacing the arrangement device to the arrangement position without the arrangement device itself having to be provided with a sensor for detecting the edge of the package. Accordingly, the return path mentioned in the description of the prior art is dispensed with. As a result, that amount of time which is required in the prior art for the return travel of the arrangement device once the edge of the package has been detected is saved in the operation of positioning the arrangement device. Even just this provides for a less time-intensive processing operation and a higher throughput of the strapping apparatus. Significant increases in the throughput speed are achieved, however, in particular when the arrangement device is moved in the direction of the arrangement position while the package is still entering, provision being made for the arrangement device to reach the arrangement position at the latest when the entering package has reached its strapping position.

Using the aforementioned method steps, it becomes clear that the amount of time required for processing a package in the strapping apparatus can be considerably reduced. By virtue of the position of the package being detected while the package is entering into the apparatus, it is possible for the first time to utilize the time taken for the package to enter in order to move the arrangement device into its arrangement position. The entire period of time which is required in the prior art described above in order to move the arrangement device into the arrangement position once the package has reached its strapping position can thus be saved. This considerably increases the throughput of packages through the strapping apparatus; the period of time taken for processing a package is considerably reduced.

It is also the case with the improved apparatus proposed here, and with the improved method proposed here, that use can be made, in addition, of the sensor which is known from the prior art and is arranged on the arrangement device itself, the sensor being configured specifically here as a photocell. It is, indeed, the case that the sensor is no longer necessary in order to determine the position of the package relative to the arrangement device, since this is already made possible by the invention beforehand. However, the sensor can be used in combination with the invention for a plausibility check. With the aid of the sensor on the arrangement device, it is possible to establish whether, while the package is entering, deviations have arisen between the calculated strapping position of the package and the strapping position which the package has actually reached. Should such deviations be established, re-positioning can also take place by means of the sensor, it still also being ensured here that a considerable amount of time is saved.

The invention will now be explained with reference to the exemplary embodiment described hereinbelow. In the drawings:

FIG. 1 shows the schematic illustration of a package entering into a strapping apparatus, the package being in a first position,

FIG. 2 shows the illustration according to FIG. 1 with the package in a second position,

FIG. 3 shows the illustration according to FIG. 1 with the package in the strapping position, and

FIG. 4 shows the illustration of a strapping apparatus.

FIGS. 1 to 3 illustrate merely the essential constituent parts of the invention; the illustration has dispensed with non-essential details of the strapping apparatus. A strapping apparatus in its entirety, in contrast, is illustrated in FIG. 4.

The strapping apparatus according to the invention is provided overall with the reference sign 10, wherein, of the strapping apparatus 10, FIGS. 1 to 3 illustrate merely a lateral-boundary component 11, in order to symbolize the lateral packaging-table periphery, and the arrangement device 12.

FIG. 4 illustrates the strapping apparatus 10 in its entirety. The strapping apparatus comprise, in the first instance, a packaging table 16, which is provided with a multiplicity of rollers 17. Vertical supports 18, which carry a press plate 19, are arranged laterally, on the right and left, in relation to the packaging table. Said press plate 19 can be displaced up and down along the vertical supports 18. All of this goes to form a portal-like machine frame through which the package 13, which is mounted on a pallet 20, is moved. A strapping-means channel encompasses the package 13, being formed from portions which are located in the press plate 19, along the vertical supports 18 and in the packaging table 16. Starting from a band store 21, a strapping band is moved, by means of an insertion and closure device, through the channel portions and around the package 13. When the end of the band arrives at the insertion and closure device, it is retained there and begins a retraction movement. During this, the band leaves the strapping channel via various opening mechanisms and is tensioned around the package.

Arrangement devices 12 for edge-protection means 14 are arranged on the press plate, but are not illustrated in FIG. 4. Proceeding from a starting position—these arrangement devices shift the edge-protection means 14 onto the edges of the package. Once the press plate (illustrated in FIG. 4) has been lowered, the edge-protection means is retained between the press plate 19 and package 13. When the band is tensioned around the package 13, the edge-protection means is positioned between the strapping band and edge of the package and thus protects the edge of the package.

In FIGS. 1 to 3, a package 13 is located on a packaging table 16, which is provided with rollers, but is not illustrated specifically in the drawings, and moves in the entry direction E the apparatus 10. In the illustrations of FIGS. 1 to 3, the arrangement device 12 is provided with an edge-protection means 14 which is to be applied to the package edge K directed toward the arrangement device 12. A position-detection means 15 is arranged on the component 11, in an entry region of the apparatus 10, and senses the distance of the package 13, said distance being represented in the figures by the reference sign X. The position-detection means 15 serves to sense the distance between the package 13 and the component 11, or itself, while the package is entering. It is, indeed, advantageous if the means 15 is arranged as closely as possible to the front boundary of the packaging table, as seen in the entry direction E.

However, this specific position is not absolutely necessary for the invention. However, it is necessary for the position-detection means 15 always to be arranged such that it can sense the distance X from the package 13 while the latter is entering. Any position in which it is possible to sense an entering package 13 is therefore conceivable. It is thus also possible for the position-detection means 15 to be arranged in the region of the vertical supports 18 (not illustrated here), or on the vertical supports (not illustrated here), since entry movement of the package 13 also takes place in this region.

FIG. 2 illustrates that the package 13 has advanced forward in the entry direction E in relation to FIG. 1. At the same time, the arrangement device 12 with the edge-protection means 14 has been moved by a distance Y in the direction of the expected strapping position of the package 13. The arrangement device 12 here moves from an actual position or starting position, in the direction of the expected strapping position of the package 13 by way of an arrangement movement A. In the present example, the arrangement movement A is directed orthogonally to the entry direction E.

FIG. 3, then, shows the situation in which the package 13 is located in its strapping position and the entry movement has come to an end. The arrangement device 12 has not advanced in relation to FIG. 2. It has maintained its arrangement position in relation to FIG. 2. In the strapping position, the package 13 is located beneath the edge-protection means 14, or the arrangement position of the arrangement device 12 is that in which the edge-protection means 14 is located above the edge K of the package 13. In this position, the actual strapping operation can then begin.

The method according to the invention provides for the position-detection means 15 to sense the position of the package 13 relative to a reference point, in this case relative to the lateral-boundary component 11. Sensing takes place here while the package 13 is entering into the apparatus in the entry direction E. Since it is also the case that the distance of the position-detection means 15 from a band channel (not illustrated) is known, a controller (not illustrated specifically) can then calculate the expected strapping position of the package 13.

Once the expected strapping position of the package 13 has been calculated, the arrangement position of the arrangement device 12 which is relevant to the package 13 is calculated. Account should be taken here of the way in which the edge-protection means 14 is to be oriented in relation to the edge K of the package. This gives a displacement distance Y which has to be covered by the arrangement device 12 in the form of an arrangement movement in direction A.

The arrangement movement A is then induced by the controller, a distance-counting unit (not illustrated) sensing the displacement distance to the arrangement position, and this ensures precise determination of the distance Y which is to be covered.

Movement into the arrangement position takes place while the package 13 is still entering into the strapping position, and therefore the arrangement device 12 has already reached the arrangement position before the strapping position is reached (see FIG. 2). The method according to the invention therefore makes it possible for the time which the package 13 requires in order to enter into the strapping position also to be utilized in order to execute the arrangement movement A. With corresponding positioning of the position-detection means 15, it is even conceivable for the arrangement device 12 to reach the arrangement position before the package 13 has reached the strapping position.

The passage of the package 13 through the apparatus 10 is therefore accelerated to a considerable extent in relation to the prior art, since the amount of time taken for positioning the arrangement device 12 once the package 13 has reached the strapping position is done away with.

It is quite conceivable for the prior-art sensor for sensing the edge K of the package also to be utilized in combination with the method according to the invention. In this case, however, rather than being used for primary control of the arrangement device 12, the sensor serves merely to provide a plausibility check. The plausibility check can be used to check whether the arrangement position has been reached correctly or whether, where the package 13 is entering, a problem has resulted in an actual strapping position which deviates from the position calculated. In this case, it would then be possible to correct the position of the arrangement device 12 with the aid of the sensor on the arrangement device 12.

LIST OF REFERENCE SIGNS

Strapping apparatus

Lateral-boundary component

Arrangement device

Package

Edge-protection means

Position-detection means

Packaging table

Rollers

Vertical supports

Press plate

Pallet

Band store

A Arrangement movement

E Entry direction

K Edge of packaging table

X Distance between 11 and 13

Y Distance 

1-7. (canceled)
 8. A strapping machine comprising: a frame at least partially defining an entryway; a packing table at least partially within the frame; a press plate movable toward and away from the packaging table; an arrangement device configured to hold an edge protector and movable relative to the packing table between a starting position and an arrangement position; a sensor configured to sense entry of a load into the entryway; and a controller configured to control the arrangement device to move from the starting position to the arrangement position responsive to the sensor sensing entry of the load into the entryway.
 9. The strapping machine of claim 8, wherein the sensor is supported by the frame.
 10. The strapping machine of claim 9, wherein the frame comprises multiple vertical supports and the sensor is arranged on one of the vertical supports.
 11. The strapping machine of claim 8, wherein the press plate is movable in a first direction toward and away from the packaging table and the arrangement device is movable in a second direction from the starting position to the arrangement position, wherein the second direction is transverse to the first direction.
 12. The strapping machine of claim 11, wherein the sensor is configured to sense entry of the load moving in a third direction into the entryway, wherein the third direction is transverse to the first and second directions.
 13. The strapping machine of claim 8, wherein the arrangement device is mounted to the press plate and movable relative to the press plate between the starting position and the arrangement position.
 14. The strapping machine of claim 8, wherein the controller is configured to, responsive to the sensor sensing entry of the load into the entryway, control the arrangement device to move from the starting position to the arrangement position so the arrangement device arrives at the arrangement position no later than arrival of the load to a strapping position on the packing table at which the load is to-be-strapped.
 15. The strapping machine of claim 8, wherein the sensor is configured to sense a distance between the sensor and the load.
 16. The strapping machine of claim 15, wherein the controller is configured to determine the arrangement position based on the sensed distance between the sensor and the load.
 17. The strapping machine of claim 16, wherein the controller is configured to determine a strapping position on the packing table at which the load is to-be-strapped based on the sensed distance between the sensor and the load, wherein the controller is further configured to determine the arrangement position based on the strapping position.
 18. The strapping machine of claim 8, wherein the arrangement device comprises a distance counter configured to determine a displacement distance of the arrangement device from the starting position.
 19. A method of operating a strapping machine to position an edge protector on a corner of a load, the method comprising: sensing, by a sensor, entry of the load into an entryway of the strapping machine; responsive to the sensor sensing entry of the load into the entryway, moving an arrangement device relative to the load from a starting position to an arrangement position as the arrangement device carries an edge protector; and after the load reaches a strapping position on a packing table, positioning the edge protector on the corner of the load.
 20. The method of claim 19, further comprising moving the arrangement device relative to the load from the starting position to the arrangement position so the arrangement device arrives at the arrangement position no later than arrival of the load to the strapping position.
 21. The method of claim 19, wherein sensing entry of the load into the entryway comprises sensing a distance between the sensor and the load.
 22. The method of claim 21, further comprising determining, by a controller, the arrangement position based on the sensed distance between the sensor and the load.
 23. The method of claim 22, further comprising: determining, by the controller, the strapping position based on the sensed distance between the sensor and the load; and determining, by the controller, the arrangement position based on the strapping position.
 24. The method of claim 19, further comprising controlling, by the controller, the arrangement device to move relative to the load from the starting position to the arrangement position responsive to the sensor sensing entry of the load into the entryway.
 25. The method of claim 24, further comprising determining, by a distance counter of the arrangement device, a displacement distance of the arrangement device from the starting position.
 26. The method of claim 19, further comprising moving a press plate into contact with a top surface of the load to hold the edge protector in position on the corner of the load.
 27. The method of claim 26, further comprising, after moving the press plate into contact with the top surface of the load, tensioning a loop of strap around the load to retain the edge protector on the corner of the load. 